Feasibility of generating ultrashort pulses by laser mode locking using a stimulated Raman scattering filter

Abstract

We propose a new frustrated Heisenberg antiferromagnetic model with spatially anisotropic exchange parameters J c , J a , and J ac , extending along the c, a, and a ± c (c-a-ca model) lattice directions, and apply it to describe the fascinating physics of copper carbodiimide, CuNCN, assuming the resonating valence bond (RVB) type of its phases. This explains within a unified picture the intriguing absence of magnetic order in CuNCN. We further present a parameters-temperature phase diagram of the c-a-ca-RVB model in the high-temperature approximation. Eight different phases including Curie and Pauli paramagnets (respectively, in disordered and 1D-or Q1D-RVB phases) and (pseudo)gapped (quasi-Arrhenius) paramagnets (2D-RVB phases) are possible. By adding magnetostriction and elastic terms to the model, we derive possible structural manifestations of RVB phase transitions. Assuming a sequence of RVB phase transitions to occur in CuNCN with decreasing temperature, several anomalies observed in the temperature course of the lattice constants are explained.

From laser-induced line narrowing to electro- magnetically induced transparency: closed system analysis

“…: 32.70.Jz, 42.50.Gy, Over the last decade, considerable attention has been paid to the studies of the atomic coherence effects and their applications [1,2]. The technique of Electromagnetically Induced Transparency (EIT) which makes an opaque medium become transparent by applying an external coherent radiation field [3,4], yields various applications from enhancement of nonlinear optical processes [5][6][7], to slow light [8][9][10][11][12][13][14]. In addition to the elimination of absorption, the absorption profile reveals a narrow transmission line, which has been applied to high resolution spectroscopy and high sensitivity magnetometer [15][16][17][18].…”

Suppression of coherent scattering by coherent population trapping on molecular vibrational levels

“…Quantum coherence effects, such as coherent population trapping (CPT) [9] and electromagnetically induced transparency (EIT) [10][11][12][13], have been the focus of broad research activity for the last two decades, as they drastically change optical properties of media. For example, for EIT in CW and pulsed regimes [11][12][13][14][15], absorption practically vanishes. The medium with excited quantum coherence, phaseonium [10], can be used to make a ultra-dispersive prism [16] that has several orders of magnitude higher angular spectral dispersion.…”

Effect of Fano Resonance in photovoltaic

“…For example, for EIT in CW and pulsed regimes [3][4][5][6][7], absorption practically vanishes. Media with excited coherence may display high index of refraction without absorption [8].…”